Avian reoviruses are associated with several diseases in poultry, including malabsorption syndrome and runting and stunting syndrome (RSS), although their role as primary pathogens in these clinical syndromes is not clear. In contrast, the association of avian reoviruses with clinical cases of viral arthritis/tenosynovitis is quite clear, as reoviruses have been isolated from the tendons of affected birds. The control of reovirus-induced viral arthritis/tenosynovitis can be achieved by vaccination of broiler breeders with a combination of live and/or inactivated vaccines with maternal immunity passed on to progeny for early protection against field challenge. In broilers, live attenuated vaccines are available for use at day-of-hatch and for use in ovo. Current commercial vaccine strains (S1133, 1733, 2408, and 2177 to name a few) have been used for decades to control diseases associated with reovirus. However, these commercial vaccine strains were isolated in the 1960-1970s and do not provide protection against currently circulating reovirus isolates from confirmed cases of viral arthritis/tenosynovitis. Thus there is a need for the isolation and characterization of currently circulating avian reoviruses and the development of effective vaccines.